robin-son



2 Sheets-Sheet 1.

J. R ROBINSON.

(No Model.)

ELECTRIC MOTOR.

' O. 464,231 lfg tented Dec. 1,1891.

(No Model. 2 shees snet 2.

J. R. RGBIN-SON.

ELECTRIC MOTOR.

o. 464,231. Patented 1390. 1 1891.

w VITNESSES Lb a M whom it may con lie news that .lOi.

alcm, in the county of E lll. "is, have invented cert ul improvements in l lectrio i) c I the following 5 description clear, and exact to ei'ia-ble i: the art or z ence to w had to t u accou orniing' part of this spool" Figure 1 is a front clove Fig. side e the base stand? motor; of 5, a bottom plan i a plan view oi the in and Figs. 5, 6, and 7, sect trating' certain details of eons.

Like letters and figures oi 1 cate corresponding parts in ures of the drawings.

Myinvention relates to a motor which is particularly ad in driving flexible shaf forth and claimed, the object beii duce a simpler, cheaper, and more off vice of this character than is now in or use.

The nature and 01 e "alien ot' the im ment will be readily understooi'l by ah versan'c with such matters from the follow expla ation:

In the drawings, A represents the and B the motor. The stand corn 3 base b,supported on legs (I and vertical standards f. 0n the bzbinding-posts g it, to which the generatorwires 2' are secured. These posts through the base. 0n the op; osite side 0-. the base two sliding posts is Zarc mounted. A wire jconnects the posts 5/ and L.- Two spring contact-arms 1'.) q are respectively secured to the lower ends of the posts 72 Z'ou the under side of the base b,"tl1e free end of the arm (I overlapping the corresponding arm 7). A springsustained plunger i, having a oval or curved head 9'; is fitted to slide vertically through the center of the base, its lower end being in engagement with theupr ccutact-arm q. Said plunger is adapted to force the arm q out of contact with the-arm wh n depressed. The motor B is supcnded verti- It, dated Eeccmber 1, 3.891.

Serial Isle. $19 592 (N0 model.)

7 cally above the olung'er by means of a gimbalgoni su" ported, in the tops ot' the stand- -i E f. The armor conipr s a l'lOi'lZOiT'tl the en of which vertica'ly-arrangcd poio- 2 w are secured. stud a: on a brace red 11 connecting the lower ends of olQpie es, is in position to engage the i e plunger r and depress the same. l 'l. is soelzeted to receive said a ainst lllt-J'fitlil'lOV-(k A vertically arted to rotate between pieces bearings 16 i ovided with sire" t 19 pro-- Lil hefacc rls from the coil, and z: cranes 23, Secured.

g 55- leads to one commu- A simi er arrangement of wires the oppositebrnsh-coil and c ml joint 3 oomnriscs an ova 'l .ich cone-point istisi 11 through indards diniilar screws ,1 'lithe sides of the ring and take Ml-6S oi the projc :tion on the The motor thus pendent can bc i .ng or oscillated when disengaged 'roni the sprin pushed plunger '6.

To illustrate the use of the motor, it is shown in connection witn. mechanism for actuating d "ial, .gical, and similar instrin'ients, hereinafter described; but i do not confine myself to such construction, as any suitable form of flexible shafting may be; secured to the motor-shaft for other purposes. .A tube 31 has its lowerend extcriorly screw-threadod (see Fig. 6) to enter the bearing projection 30, which is tapped and threaded to receive it. The motor-shaft 19 is chambered longitudinally to receive a shaft 32, which is fitted to- A loose sleeve 35 is fitted to' acting expansively to force the sleeve downward. A shaft 39 isjournaled in the upper ends ofthe arms 36. A rubber-tired friction- :fivheel lO, mounted on said shaft, bears against opposite contact p.

the'disk @Bttne spring 38 holding it firmly in contact therewith. To one end of said shaft a flexible shaft ll is secured, said flexible shaft bearing a tool-chuck 42 and being of the. ordinary construction employed for actuating'dental drills and tools. A holder 13 for said shaft is seen-red to the tube 31. v

In the use of my improvement, the tube 31 "being moved laterally, the motor stud m is dispressing it or breaking the circuit. \Vhen not in use, the plunger is forced downward against the pressure of its spring and the stud a", inserted in the socket in the plungerhead, as in Fig. 2. This forces the contact (1 downward,breaking the circuit and stopping the motor. The disk 34: on the shaft 82 being held in engagement with the friction-wheel drives said wheel and the flexible shaft 41 as said shaft 32 rotates.

By providing the motor with a vertical rotary armature, as desorib d, I increase the efiiciency and effect results not attained when a horizontal armature is used. In such construction the line of shortest magnetic circuit is in the inner or lower portion of the poles and more lines of force pass therefrom to the armature. By my construction the strength of field is equal on bothsides, ov rcoming any tendency to spark from a dis torted field of magnetism.

Having thus explained my invention, what I claim is 1. The combination of a stand or support with a swinging electric motor suspended by a gimbal-joint from said stand, substantially its-described.

2. In a device of the character described, a support provided with binding-posts for the generator and motor wires, in combination with'an electric motor mounted to swing in said support and a circuit-closer for automatically closing theelectric circuit in said wires when the motor isswinging and breaking the same when said motor is stationary in perpelulicular position, substantially as described.

3. In a device of the character described, a stand or support, in combination with an electric motor mounted 'to swing thereon,

binding-posts for the generator and motor- Wires,spring-contacts for closing the circuit between said wires, and a spring-pushed plunger inengagement with one of said cont-acts and disposed in position to be engaged by the swinging motor and depressed to break said circuit, substantially as described.

4. In a'deviee of the character described,

an electric circuit, a stand, as A, an electric motor mounted to swing in said stand, a cireuit-breaker disposed in. position-to be engaged by said motor and depressed to break the circuit when .the motor is stationary in perpendicular position andad'apted to automatically close said circuit when the motor is swinging, a detachable shaft secured to the motor-shaft, and mechanism for attaching a flexible shaft thereto, substantially as described. 5-. In a device of the character described, a stand or support, as A, provided with bind ingpostsgxh k l, the -connecting-wire j,'and spring-contacts q p, the spring-pushed plunger r in engagement with one of said contacts, an electric circuit, and an electric motor in said circuit, said motor being mounted to swing in said support in position to engage anddepress said plunger, all being combined and arranged to operate substantially as set forth.

6. In a device of the character described,

the combination of 'a support with an electric motor disposed in a generator-circuit and mounted to swing in said support, and mechanism. actuated mechanically by said motor forbreaking said circuit, substantially as described.

7. In a device of the character described, I

the electric mot-or B and its support, in combination with the tube 31 and inclosed-shaft 32, detachably secured to the motor-shaft, a

disk on said incloscd shaft, a spring-pushed bracket on said sleeve, a shaft journaled in said bracket and having a friction -wheel' bearing on said disk, and atlexible tool-shaft detachably secured to said wheel-shaft, substantially as described.

8. An electric circuit and the stand A, provided with spring-contacts p q, normally closing said circuit, in combination with the spring-sustained plunger 7, engaging one of said contacts, an electric motor mounted to swing in said stand, and a stud on said motor adapted to engage and depress said plunger, whereby the circuit may be broken, substantially as described.

9. The motor 15, mounted to swing in a supportand comprising the horizontal coil,

vertical pole-pieces w, secured thereto, the vertical rotary armature 1'5, disposed between the heads of said poles,the commutator and shaft, and the insulator-bar bearing contact-brushes, all being arranged to operate snbstantiallyas'described.

JOHN R. ROBINSON." Nitnesses: I

A m-run A. Fomvnss, CHARLES ll. ()DELL. 

